RFID systems for vehicular applications

Abstract

An indication system ( 10 ) for a vehicle ( 11 ) includes a radio frequency circuit ( 12 ) with a transponder ( 84 ) and an in-vehicle RF tagged element ( 18 ). The transponder ( 84 ) transmits a status request signal. A first radio frequency identification tag ( 84 ) is coupled to the in-vehicle RF tagged element ( 18 ). The tag ( 84 ) inductively generates a current status signal associated with the in-vehicle element ( 18 ) and in response to the status request signal. A method of tracking, identifying, and determining the presence and status of an in-vehicle RF tagged element ( 18 ) includes transmitting a status request signal. The status request signal is inductively received via multiple radio frequency identification tags ( 84, 86 ) that are associated with the in-vehicle RF tagged element ( 18 ). A current status signal is transmitted from the radio frequency identification tags ( 84, 86 ). An in-vehicle task is performed in response to the current status signal.

1. An indication system for a vehicle, said indication system comprising:
 at least one in-vehicle element including at least one seat system having an associated seat belt tongue and seat belt buckle; 
 a first radio-frequency circuit including (i) a transponder operable to transmit a status request signal and (ii) a first radio-frequency identification tag coupled to said at least one in-vehicle element and operable to inductively generate a first status signal associated with said at least one in-vehicle element in response to said status request signal; and 
 a second radio-frequency circuit including a second radio-frequency identification tag coupled to said at least one in-vehicle element and operable to inductively generate a second status signal; 
 wherein when said seat belt tongue is latched within said seat belt buckle, said first radio-frequency circuit is inactive and said second radio-frequency identification tag is active. 
 
     
     
       2. A system for generating an indication of an operational status of an in-vehicle element comprising:
 an in-vehicle element; 
 a first radio-frequency tag that is associated with the in-vehicle element and that is operable to generate a first identification-and-status information signal for the in-vehicle element in response to a status request signal, wherein the first identification-and-status information signal includes an identification and a first operational status of the in-vehicle element; 
 a second radio-frequency tag that is associated with the in-vehicle element and that is operable to generate a second identification-and-status information signal for the in-vehicle element in response to the status request signal, wherein the second identification-and-status information signal includes an identification and a second operational status of the in-vehicle element; 
 wherein when the in-vehicle element is in a predetermined operating status, the first radio-frequency tag is inactive and the second radio-frequency identification tag is active; 
 a controller that is responsive to the first and second identification-and-status information signals for generating a signal that is representative of the identification and the operational status of the in-vehicle element; and 
 an indication device that is responsive to the signal from the controller for generating an indication of the operational status of the in-vehicle element. 
 
     
     
       3. The system defined in  claim 2  wherein the in-vehicle element is one of a door, a window, a seat, a hood, a trunk lid, a countermeasure device, a fluid level switch, a load limit switch, a pressure switch, and an illumination device. 
     
     
       4. The system defined in  claim 2  wherein the in-vehicle element is a seat belt system having a seat belt tongue and a seat belt buckle associated therewith. 
     
     
       5. The system defined in  claim 4  wherein the indication device indicates whether the seat belt tongue is latched within the seat belt buckle. 
     
     
       6. The system defined in  claim 2  further including a delay circuit that is operable to prevent the first and second identification-and-status information signals from being generated simultaneously.